1. Field of the Invention
Aspects of the present invention relate to an image forming apparatus, and more particularly to an image forming apparatus having a power transmission device that intermittently transmits power to a driven component from a driving source.
2. Related Art
An image forming apparatus is an apparatus that prints an image onto a printable medium, such as paper, according to an inputted image signal. Although image forming apparatuses include different components depending on the type of the image forming apparatus, image forming apparatuses generally include a paper supply unit that supplies a printable medium, a print unit that prints an image onto the printable medium, and a paper discharge unit that discharges the printed printable medium.
The paper supply unit, the print unit, and the paper discharge unit include various components, such as rollers, photosensitive bodies, belts, etc., to perform the paper feeding operation and the printing operation. These components are driven by a driving source, such as a motor. In order to save component costs, it is preferable to use as few motors as possible. Thus, in many cases, the image forming apparatus is constructed so that multiple components are driven by a single motor. For this purpose, a power transmission device is disposed on a path through which power from the motor is transmitted to the components. The power transmission device transmits power only to the components needing to be driven, and interrupts power to the components that do not need to be driven.
An electronic clutch is conventionally used as the power transmission device. However, electric current should be continuously applied to the electronic clutch. Accordingly, when successively transmitting power over a long period of time, heat is generated from the electronic clutch, reducing performance and contributing to malfunctions.
A malfunction of the electronic clutch may cause rough printing operation or a decrease in image quality. For example, if the electronic clutch malfunctions so that power is not transmitted to the developing device at the correct time, toner cannot be supplied and the image may not be developed well on the printable medium. If the electronic clutch malfunctions so that power is transmitted to the developing device when the developing device should not operate, the toner in the developing device is unnecessarily subject to stress and a decrease in quality, resulting in deterioration of image quality.